Data-driven high-throughput search for the accelerated discovery of rare-earth-free permanent magnets

Abstract: An integrated data-driven approach combined with a high-throughput framework based on first-principles calculations was used to discover novel rare-earth-free permanent magnets, focusing on binary alloys. Compounds were screened systematically based on their elemental composition, structure, stability, and magnetization. Density functional theory (DFT) calculations were performed on the selected candidates to evaluate their magnetocrystalline anisotropy energy (MAE) and Curie temperature (Tc), resulting in the identification of ten promising materials. A thorough literature review was done to assess reports of prior existence, which confirmed the novelty of ZnFe and Fe8N. Their ferromagnetic ground state was re-established through DFT, and structural stability was confirmed via negative formation enthalpies, phonon spectra, and elastic criteria. Tetragonal ZnFe and Fe8N exhibit high saturation magnetization (>1 T), large anisotropy constants (>0.5 MJ/m^3), and high Tc (>1200 K). Their magnetic hardness parameters (kappa = 0.85 for ZnFe and 0.70 for Fe8N) further support their potential as gap magnets. These findings highlight the efficacy of our high-throughput screening, which may serve as a theoretical blueprint for the experimental realization of these materials.